The present invention relates to medicament delivery devices and, more particularly, to devices for administering inhalable medicaments.
Inhalers are commonly used to deliver various medicaments to users via the user""s nose or mouth. Such medicaments increasingly include dry powders. A number of considerations affecting the efficacy of delivery may be presented, particularly in the case of dry powders. For example, it may be important to ensure that the appropriate dose is metered and expressed, that the medicament is properly dispersed in the conveying fluid (e.g., the carrier gas), that the delivery device is not unduly susceptible to user error in operation, and/or that undue inhalation strength is not required. Further considerations may include the operating complexity, portability and size of the delivery device. Because inhalation therapy often requires numerous applications, the cost of providing the dosage may be of particular importance.
According to embodiments of the present invention, a medicament delivery device for administering a medicament to a user includes a medicament reservoir and an entrance port and an exit port each disposed adjacent the reservoir. A gas chamber is disposed adjacent the entrance port. The device includes a pressurizing mechanism operable to pressurize the gas chamber to at least a prescribed pressure. A first frangible membrane extends across the entrance port and separates the reservoir from the gas chamber. A second frangible membrane extends across the exit port. When the pressurizing mechanism is attached, at least one of the first and second membranes is responsive to the prescribed pressure in the gas chamber to burst to allow gas to flow through the entrance port and the reservoir and to carry the medicament through the exit port.
The pressurizing mechanism may include a compressible blister defining the gas chamber and operable to pressurize the gas chamber to at least the prescribed pressure. The device may include: a first sheet including the compressible blister formed therein; a second sheet defining the reservoir therein; and an intermediate layer disposed between the first and second sheets, the first and second membranes forming a part of the intermediate layer.
According to further embodiments of the present invention, a medicament delivery device for administering a medicament to a user includes a medicament reservoir and an entrance port and an exit port each disposed adjacent the reservoir. The device includes a compressible blister defining a gas chamber and operable to pressurize the gas chamber to at least a prescribed pressure. A frangible membrane extends across the entrance port and separates the reservoir from the gas chamber. When the blister is compressed, the membrane is responsive to the prescribed pressure in the gas chamber to burst to allow gas to flow through the entrance port and the reservoir and to carry the medicament through the exit port.
According to further embodiments of the present invention, a method for administering a medicament to a user includes providing a medicament delivery device including: a medicament reservoir; an entrance port and an exit port each disposed adjacent the reservoir; a gas chamber disposed adjacent the entrance port; a pressurizing mechanism operable to pressurize the gas chamber to at least a prescribed pressure; a first frangible membrane extending across the entrance port and separating the reservoir from the gas chamber; and a second frangible membrane extending across the exit port. The pressurizing mechanism is actuated to generate the prescribed pressure in the gas chamber, whereupon at least one of the first and second membranes bursts to allow gas to flow through the entrance port and the reservoir and to carry the medicament through the exit port.
According to further embodiments of the present invention, a method for administering a medicament to a user includes providing a medicament delivery device including: a medicament reservoir; an entrance port and an exit port each disposed adjacent the reservoir; a compressible blister defining a gas chamber and operable to pressurize the gas chamber to at least a prescribed pressure; and a frangible membrane extending across the entrance port and separating the reservoir from the gas chamber. The blister is compressed to generate the prescribed pressure in the gas chamber, whereupon the frangible membrane bursts to allow gas to flow through the entrance port and the reservoir and to carry the medicament through the exit port.
Objects of the present invention will be appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the preferred embodiments which follow, such description being merely illustrative of the present invention.